2026 NPPES data Internal Medicine Physician NPI 1457647133 M.D.
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MERRICK DONENBERG, M.D.

Internal Medicine Physician in OTTAWA, Illinois. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
6K
Medicare Part D claims · 678 beneficiaries · Internal Medicine Physician avg: 3K

What the federal data shows

MERRICK DONENBERG, M.D. filed 5,833 Medicare Part D claims in 2023 as a Internal Medicine Physician in OTTAWA, Illinois.

6K
Part D claims, 2023
Likely
board-certified (heuristic)

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

MERRICK DONENBERG, M.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

5,833 Top 5% higher than 95% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

MERRICK DONENBERG, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

What does the federal data show about MERRICK DONENBERG, M.D.?

Quality data not reported

NPI registry status

Active

Issued 06/21/2011

NPI 1457647133

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

5,833 115% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Illinois

How Internal Medicine Physician compares to other specialties among Illinois providers

Illinois providers

Internal Medicine Physician share within Illinois

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within Illinois

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Internal Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

MERRICK DONENBERG, M.D. appears in the CMS NPPES registry as a Internal Medicine Physician provider holding M.D. credentials at 1050 E NORRIS DR STE 2C, OTTAWA, IL, 61350, with a listed phone of (815) 434-0276. NPI 1457647133 was issued on 06/21/2011. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DONENBERG most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 5,833 prescription claims written by this provider, covering 678 Medicare beneficiaries and totaling roughly $1.3 million in drug spend. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

1050 E NORRIS DR STE 2C
OTTAWA, IL 61350

Provider Details

NPI 1457647133
Specialty Internal Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 06/21/2011

Hospital and facility affiliations

Facilities where MERRICK DONENBERG, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

OSF MULTI-SPECIALTY GROUP
OTTAWA, IL

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

License & disciplinary context — Illinois IDFPR 2023 annual report

Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~42K Illinois medical licensees in 2023 — they are NOT specific to MERRICK DONENBERG, M.D.. To verify MERRICK DONENBERG, M.D.'s current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases

IDFPR publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

5,833
Total Claims
$1.3M
Total Drug Cost
678
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
15,848
Total Day Supply
473,274
Generic Drug Cost
$116K
Antibiotic Claims
15

Patient Demographics

Average Patient Age
75.4 years
Avg HCC Risk Score
1.69
Gender Split
44% female / 56% male
Age Distribution
<65: 40, 65-74: 273, 75-84: 265, 85+: 100

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What MERRICK DONENBERG, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
831
Rosuvastatin Calcium
451
Carvedilol
446
Metoprolol Succinate
380
Spironolactone
309
Amlodipine Besylate
307
Eliquis
Apixaban
298
Losartan Potassium
288
Furosemide
255
Lisinopril
251

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Internal Medicine Physician Overview

How MERRICK DONENBERG, M.D. fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

MERRICK DONENBERG, M.D.'s 5,833 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Illinois

Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as DONENBERG.

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is MERRICK DONENBERG, M.D.'s specialty?
MERRICK DONENBERG, M.D. specializes in Internal Medicine Physician and practices in OTTAWA, Illinois. Credentials: M.D..
How much does MERRICK DONENBERG, M.D. prescribe under Medicare Part D?
In 2023, MERRICK DONENBERG, M.D. wrote 5,833 Medicare Part D claims totaling $1.3M in drug costs for 678 beneficiaries.
Where is MERRICK DONENBERG, M.D. located?
MERRICK DONENBERG, M.D. is located at 1050 E NORRIS DR STE 2C, OTTAWA, IL, 61350. Phone: (815) 434-0276.
What is MERRICK DONENBERG, M.D.'s NPI number?
MERRICK DONENBERG, M.D.'s National Provider Identifier (NPI) is 1457647133, issued on 06/21/2011.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does MERRICK DONENBERG, M.D. prescribe most often?
Based on 2023 Medicare Part D data, MERRICK DONENBERG, M.D.'s most frequently prescribed drugs include Atorvastatin Calcium, Rosuvastatin Calcium, Carvedilol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MERRICK DONENBERG, M.D. accept Medicare?
MERRICK DONENBERG, M.D. appears in CMS Medicare data with 5,833 Part D claims and 678 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MERRICK DONENBERG, M.D.'s credentials?
MERRICK DONENBERG, M.D.'s NPI is 1457647133 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology